The present invention relates in general to field emission devices, and in particular, to field emission devices utilizing carbon nanotubes.
Carbon nanotubes/nanofibers have attracted much interest because of their unique physical properties and many potential applications. One significant application is as field-emission electron sources. These sources can find themselves imbedded in other applications such as displays, x-ray sources, microwave devices, satellite thrusters, etc. Carbon nanotubes were first discovered by Iijima, (see S. Iijima, Nature (London) Vol. 354, p. 56, 1991 which is hereby incorporated by reference herein). Since then, many have developed several methods of fabricating the material. For field emission source applications, the state of the art is to either fabricate the tubes in a reactor and then place them on a substrate surface, (see Sashiro Uemura, Junko Yotani, Takeshi Hagasako, Yahachi Saito and Motoo Yumura, xe2x80x9cHigh-Luminance Carbon Nanotube FEDxe2x80x9d, SID 2000 Digest of Technical Papers, p. 320 (2000); and P. G. Collins and A. Zettl, Appl. Phys. Lett., Vol. 69, p. 1969 (1996)) or grow them directly onto the substrate surface. The latter method is generally preferred since the field emission properties of the resulting film are not degraded by the presence of binders and adhesives to secure the carbon nanotubes to the substrate.